Improvement in metal-drilling machines



E. N. BOYNTON, GOBURN- & T. P. CARVER. 'Metal-Drilling Machine.

Patented Nov. 5,-1878.

WITNESSES N-PEKERS, FNOTD-LITHOGRAPHER ASHINGTON D :INVBNTOR:

eff/#73 7W/ 5? w ATTORNEYS.

j'UNr En STATES PATENT 'FFICE.

EDWIN N. BCYNTON, GEORGE M. COBURN, AND THOMAS F. CARVER, OF WORCESTER,MASSACHUSETTS, ASSIGNORS TO EDWIN N. BOYNTON,

OF SAME PLACE.

IMPROVEMENT IN METAL-DRILLING MA C HI NES.

Specification forming part of Letters Patent N 0. 209,646, datedNovember 5, 1878; application filed August 6, 1878.

To all whom it may concern:

"Be it known that we, EDWIN N. BOYNTON, GEORGE M. (303mm, and THOMAS F.CARVER, all of Worcester, in the county of Worcester and State ofMassachusetts, have invented a new and Improved Drilling-Machine, ofwhich the following is a specification:

In the accompanying drawings, Figure 1 represents afront elevation, Fig.2 a side eleand the feed mechanism is thrown out of op erationautomatically when the spindle arrives at its lowest position, so as toprevent the grinding out of the nut or collar on the top of the spindle.

The invention will first be described in connection with the drawing,and then pointed out in the claim.

Referring to the drawings, A represents the upright main frame of ourimproved drillingmachine, which guides, in vertical bearings a, thespindle B of the drill, while a horizontal side frame, A, forms, inconnection with the main frame, the bearings for the two drivingshafts CC. The front or driving shaft, C, revolves, by bevel-gears d d, thespindle directly when the actuating-crank D is affixed to the end of thesame, while a secondary set -of gear-wheels, e e, connects the second orrear shaft, C with the front shaft, and operates thereby the spindle.The rear shaft, 0, is extended at both sidesat one side to receive thecrank D, at the other side for a flywheel, C

As the crank D may be attached to the ends of the front or rear shaft,two different speeds may be obtained. When the crank is applied to thefront or driving shaft proper, a fast speed is obtained, while when itis attached to the rear or balance-wheel shaft a slower motion, but morepower, is obtained. The slower motion is more desirable whenlarge holesare to be drilled, as this can be done with greater ease than in thecommon drills.

The foot-piece E of the drill is fitted and clamped to a vertical post,A, of the main frame, and provided with a round or other table, E, thatis either pivoted to a fixed stud or pin, f, of the foot-piece or to thepost A as desired. The front part of the table is locked rigidly'to therecessed or forked front part of the foot-piece by a bottom ledge, g, ofcorresponding shape, so as to be retained reliably in position forholding the work placed thereon.

When tires of wheels or other articles are to'be drilled in which thetable is not wanted, it is raised clear of the foot-piece and swung outof the way, as shown in Fig. 3, the tires or other work being placed fordrilling over the recessed or forked part of the foot-piece.

The drill is fed by the usual feed mechanism, that is operated by afulcrumed and spring acted lever, F, with an anti-friction roller, h, atthe lower end, and a pivot-pawl, h at the upper end. The anti-frictionroller is engaged by a cam, h, keyed to front shaft, C, so as tooscillate the lever F, and thereby the pawl, so that the latter engagesthe ratchet h of the feed-wheel F, and turns it thereby. The feedwheelworks by an interiorly-threaded. nut the threaded upper part of thespindle, and feeds thereby the drill down to the work.

out of action when the spindle is down to its full extent by means of afulcrumed releasing- -lever, G, having'a lower forward-extending collar,B, on the top of spindle bears on the lower arm of the lever G andthrows the lever forward, so that the upper side arm presses on thefeed-lever F and supports the same clear of the cam, so that the feed isinterrupted.

The action of the lever Gr protects the nut or collar of the spindleagainst being worn or ground out in course of time by the careless-Thefeed mechanism is automatically thrown arm, 1', and an upper sidearm, t". A nut or claim as new and desire to secure by Letters Patent-The combination of the lever G, having arms 'i 13', the spindle 13,having collar B, and

the feed-lever F, as and for the purpose specified.

EDWIN N. BOYNTON. GEORGE M. OOBUBN. THOMAS F. CARVER. Witnesses:

H. M. RICE, MICHAEL J. LAVIN.

